Couple of things I learned in my research before I did this project.:
Be sure that your foot pedal recessed area will not hold water at all. I drilled a couple more holes in corners. There are electronic components in the pedal assemebly that make it much more sensitive to a bath of water. The slot down the side of the shaft seems to be a good place to align and strap the sonar cables but be careful- some cables are thick enough that you need to avoid pinching them in the plastic fork that guides the shaft into place when you lift the motor. In that slot you force the cable to bind in the "fork" guide on the shaft. Pinch marks on cables will void warranties on these. Although I used zip ties, it is recommended to use electrical tape instead because of this issue. The Garmin unit I have on the bow has a thinner cable than some, so I got by with using the slot. When I get a new Hummingbird unit I will followup with what I've pointed out here. This Ipiot link system is in this unit. I was able to get it for less that the cost of the standard issue by buying a manufacturer refurbished unit. It looked like it had never been out of the box. Downside is you only get 1 year of warranty but I saved nearly $1,000 on the purchase.
I'm adding a couple of notes here:
My Z18 had a 50Amp breaker on the troll motor wiring at the batteries. That needs to be changed to a 60Amp breaker for the Ultrex. Manual says that the motor draws as much as 56 Amps under load. I bought one from Amazon that was half the price of a Minn Kota breaker, has a manual disconnect switch, and was highly rated by purchasers. Also, be sure to put a 1 (one) Amp fuse in line on the electronic compass wiring. The manual calls for that and I didn't find a singe reference to that anywhere online in the "how to do it" videos.